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-rw-r--r--Documentation/driver-api/firmware/request_firmware.rst14
-rw-r--r--drivers/base/firmware_loader/main.c24
-rw-r--r--include/linux/firmware.h3
3 files changed, 41 insertions, 0 deletions
diff --git a/Documentation/driver-api/firmware/request_firmware.rst b/Documentation/driver-api/firmware/request_firmware.rst
index cc0aea880824..cf4516dfbf96 100644
--- a/Documentation/driver-api/firmware/request_firmware.rst
+++ b/Documentation/driver-api/firmware/request_firmware.rst
@@ -44,6 +44,20 @@ request_firmware_nowait
.. kernel-doc:: drivers/base/firmware_class.c
:functions: request_firmware_nowait
+Special optimizations on reboot
+===============================
+
+Some devices have an optimization in place to enable the firmware to be
+retained during system reboot. When such optimizations are used the driver
+author must ensure the firmware is still available on resume from suspend,
+this can be done with firmware_request_cache() insted of requesting for the
+firmare to be loaded.
+
+firmware_request_cache()
+-----------------------
+.. kernel-doc:: drivers/base/firmware_class.c
+ :functions: firmware_request_cache
+
request firmware API expected driver use
========================================
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 2913bb0e5e7b..eb34089e4299 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -657,6 +657,30 @@ int request_firmware_direct(const struct firmware **firmware_p,
EXPORT_SYMBOL_GPL(request_firmware_direct);
/**
+ * firmware_request_cache: - cache firmware for suspend so resume can use it
+ * @name: name of firmware file
+ * @device: device for which firmware should be cached for
+ *
+ * There are some devices with an optimization that enables the device to not
+ * require loading firmware on system reboot. This optimization may still
+ * require the firmware present on resume from suspend. This routine can be
+ * used to ensure the firmware is present on resume from suspend in these
+ * situations. This helper is not compatible with drivers which use
+ * request_firmware_into_buf() or request_firmware_nowait() with no uevent set.
+ **/
+int firmware_request_cache(struct device *device, const char *name)
+{
+ int ret;
+
+ mutex_lock(&fw_lock);
+ ret = fw_add_devm_name(device, name);
+ mutex_unlock(&fw_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(firmware_request_cache);
+
+/**
* request_firmware_into_buf - load firmware into a previously allocated buffer
* @firmware_p: pointer to firmware image
* @name: name of firmware file
diff --git a/include/linux/firmware.h b/include/linux/firmware.h
index d4508080348d..41050417cafb 100644
--- a/include/linux/firmware.h
+++ b/include/linux/firmware.h
@@ -85,4 +85,7 @@ static inline int request_firmware_into_buf(const struct firmware **firmware_p,
}
#endif
+
+int firmware_request_cache(struct device *device, const char *name);
+
#endif